Colorectal cancer is the third most common diagnosed cancer in both men and women and the second leading cause cancer deaths in the U.S.
Colonoscopy and computed tomography colonography (virtual colonoscopy) are accepted methods for evaluation of the colon and screening for colorectal cancer. While the following document will use the term “colonoscopy” for simplicity, it is intended that this term will also include virtual colonoscopy within its range of meaning.
The diagnostic accuracy and the therapeutic safety of colonoscopy depend on the quality of the colonic cleansing or preparation. The ideal preparatory regime for colonoscopy would reliably empty the colon of all fecal material in a rapid fashion without causing damage to the colonic tissues. An ideal preparation would also minimize or eliminate any patient discomfort.
Common preparations for cleansing include diet in combination with a cathartic agent, polyethylene glycol preparations, gut lavage and phosphate preparations (oral sodium phosphate and tablet form of sodium phosphate).
The use of these technologies has significant limitations, including:                Significant inconvenience for the patient. Most patients complain of discomfort and it is not uncommon for patients to report an inability to tolerate the colon-cleansing preparation. Complaints may relate to the unpalatable taste and large volume of the preparation, nausea and vomiting, or abdominal cramping and bloating.        Patient unwillingness to take a bowel preparation is an important barrier to colorectal cancer screening.        In some patients colonic preparation is inadequate, resulting in poor diagnostic accuracy and often requiring a repetition of the preparation and the procedure. Inadequate bowel preparation for colonoscopy can result in missed lesions, cancelled procedures, increased procedural time, and a potential increase in complication rates.        
There have also been a number of attempts to develop intra-colonic devices and systems that may be used to cleanse the large intestine prior to colonoscopy. Some of these prior art devices are intended for use in conjunction with colonoscopes; for example, they may be designed to be inserted through the colonoscope working channel or attached externally thereto (e.g. US 2005/261553). In other cases, the cleansing device is constructed as a stand-alone instrument, not requiring the participation of an endoscope. An example of such a device is found in U.S. Pat. No. 4,842,853, which describes an intra-colonic catheter device comprising separate suction and irrigation channels. However, this device is primarily intended for use in colonic irrigation (rather than pre-colonoscopy cleansing), and as such has an expanded head region that is designed to frictionally engage with the colonic wall. While this design permits the device of U.S. Pat. No. 4,842,853 to perform irrigation within the descending colon (as described in the patent), the expanded head region would be problematic for negotiating the 90 degree bends encountered when attempting to move the device in and out of the transverse colon. Consequently, this device does not provide a practical solution to the problem of pre-colonoscopy preparation.
There is therefore a need for a non-traumatic colonic preparation method and/or device, which is able to reliably and safely clean the colon prior to colonoscopy, and which assures adequate preparation and reduces or eliminates the need for oral colonic preparations, thus preventing patient discomfort and side effects such nausea and vomiting. Such a method and device may significantly increase patient compliance for screening colonoscopy, improve the chances for early colorectal cancer detection—and thus improve the survival rate from this disease and improve the accuracy of the colonoscopy procedure due to improved quality of cleansing.
Inflammatory Bowel Disease (IBD), including Crohn's disease and Ulcerative Colitis are prevalent diseases, causing significant morbidity. Treatment of IBD often requires medications such as anti-inflammatory agents, corticosteroids and chemotherapeutic agents which have multiple side-effects when administered orally. This has led to the use of enema administration of selected medications for IBD in an attempt to treat local colonic disease, while reducing side effects in other target organs.
Enema administration of medications for IDB is limited due to the fact that the medication reaches a limited area of the colon, and colonic parts which are distal from the anus, such as the transverse and ascending colon, cannot be treated with this method. This results in a large patient population which cannot be treated by a localized colonic treatment regimen and is thus exposed to the side effects of oral administration.
Thus, there would be a significant clinical advantage if a device were available which could be used to administer medications to remote portions of the colon, especially if this could be performed in a manner which is minimally invasive to the patient and does not require significant patient preparation.
It is a main purpose of the present invention to provide a device which may be used to cleanse the colonic lumen in a reliable and safe manner while preventing or minimizing trauma to the colonic wall.
It is a further purpose of the present invention to provide a device which may also be used for the local administration of therapeutic agents to all parts of the colonic epithelium.
Further aims and objects will become apparent as the description proceeds.